Posterior scalene

Muscle parts

None

Latin name

Musculus scalenus posterior

Latin muscle parts

None

Group

Cervical wall – lateral musculature – external layer

Etymology

The English name for this muscle is the muscle with three unequal sides that is behind. Scalenus is Latin for “having three unequal sides,” which comes from the Greek skallein meaning “to hoe, or stir up.” The name of the scalene muscles can be traced back to the 17th century French anatomist Jean Riolan. He thought that the three scalenes were one muscle and he envisioned their combined shape as that of an irregular three-sided, or scalene, triangle.Posterior is from the Latin post meaning “behind or after.”

Origin

Tips of the posterior tubercles of the transverse processes of C4, C5, and C6

Insertion

External surface of the second rib posterior to the tubercle for the serratus anterior

Action

Laterally flexes the lower cervical vertebrae; elevates the second rib.

Nerve supply

Branches of the ventral rami of cervical spinal nerves (C6, C7, and C8)

Blood supply

The ascending cervical and various muscular branches from the inferior thyroid, which is a branch of the thyrocervical trunk of the subclavian artery, supply the muscle. It also receives blood from the suprascapular artery, the superficial cervical artery, and the first posterior intercostal artery.